[Gem] Citrine

[Argmaster]

This is a proposal to add citrine gem stone to the game.

Physical properties:

• hardness in Mohs scale: >=7
• density (at 20° C): 2.65 g/cm3

In game properties:

• behavior similar to gemstones - provide special effect instead of stats
• can be used as tip similarly to diamond, but it has lower damage due to lower hardness

Modifiers

#TODO - moved energy-steal to sapphire, need new modifier idea

Spawn rules

• -6000 < Z < -1000
• Never spawns in veins

Related to: #1269

[IntegratedQuantum]

I think this is something that should be tried in an addon/mod first.

I'm closing this as per the content guidelines, see discussion in #1705